The present invention relates to a sheet classifying apparatus and method that perform so-called rearrangement of mailpieces, i.e., rearrange a plurality of sheets, and in particular, mailpieces, in order based on classification information by classifying and stacking the sheets in classifying boxes corresponding to the classification information added to the surfaces of the sheets or mailpieces.
In a mail delivery system, first, the mailpieces are classified in units of destination areas based on the recognition results of postal codes written/printed on the surfaces of the mailpieces to correspond to the destination areas (the first classifying operation). After the mailpieces are classified, they are rearranged, in accordance with the addresses and the like written/printed on the mailpieces, in the delivery route order with which the mailpieces are delivered (the second classifying operation).
In a conventional mail delivery system, as disclosed in, e.g., AUTOMATION AND RETAIL EQUIPMENT, March 1992, the stage of classifying the mailpieces is units of destination areas as the first classifying operation is performed automatically by using, e.g., a bar code sorter. After the mailpieces are classified in units of destination areas, they are rearranged manually in the delivery order. With this method of rearranging the mailpieces manually, rearrangement is hard to eliminate errors, and is cumbersome and time-consuming. From these reasons, it is requested that the operation of classifying the mailpieces and rearranging them in the delivery order (to be referred to as rearrangement hereinafter) be performed entirely automatically.
A sheet classifying apparatus that performs this rearrangement is proposed in Japanese Patent Laid-Open No. 8-66661.
In this proposed sheet classifying apparatus, first, paper sheets sent one by one from a supply section are classified and stacked in accordance with classification information in a plurality of classifying boxes having feed-out mechanisms. After the first classifying operation is ended, the sheets that are fed out in the stacked state from the respective classifying boxes continuously in a predetermined classifying box order are reset in the supply section. The sheets set in the supply section are fed out again one by one, and are classified and stacked in the classifying boxes in accordance with classification information. These operations are repeated until rearrangement is completed. If a classifying box in which classified sheets are to be stacked is full, the sheets are classified and stacked in an overflow classifying box.
In the sheet classifying apparatus described above, the pieces of classification information are assigned to the respective classifying boxes such that the sheets are classified and stacked in the corresponding classifying boxes in accordance with the pieces of classification information, without considering the numbers of sheets to be stacked in the respective classifying boxes.
Therefore, in the second classifying operation, if the count of sheets to be classified in the first classifying box is 0 and the number of sheets to be classified in the second classifying box is large, despite that the first classifying box is empty, overflow occurs in the second classifying box.